Traditionally and historically, load-bearing stone masonry has been the most desirable and widely used system of construction. Traditional masonry construction systems are becoming economically less competitive (and conversely are contributing to the spiraling costs of construction) as a result of increasing on-site labor costs and a decreasing amount of quality material and skilled labor supply.
Conventional concrete masonry product manufacture cakes sand, gravel, portland cement and water and molds them together (usually with vibration) to attain homogeniety and enough compaction to obtain sufficient "green" strength in the products to be transferred onto pallets to steam-curing kilns or autoclaves to obtain their ultimate strength and physical characteristics. As with brick kilns, this mandatory curing process adds an additional and costly manufacturing step both in terms of capital investment and operating expenses. Because of the way in which they are made, and because of the nature of the aggregates used, concrete masonry products are generally "crude" in finish and texture and do not have the same exacting quality requirements, durability, or imperviousness as brick. And as with bricks, concrete masonry products must be mortared together using a thick adhesive bed to compensate for their inherent "roughness".
A construction assembly of such fired clay products thus requires the use of thick mortar joints which not only adhere the bricks together but also correct for the imprecisions and dimensional discrepancies inherent to the bricks. This heat-caused distortion also limits the practical and economical production and utilization of snug fitting interlocking fired clay products. Also, in conventional masonry construction, mortar is used as the necessary sealant to obtain weathertightness between the brick structural members.
The use of thick mortar joints to assemble conventional masonry is economically burdensome, because of the specialized labor and quality of workmanship needed. The use of thick mortar joints has other objections, especially in regard to long term maintenance in that it reduces strength and durability and creates inherent problems of weatherproofing.
Traditional masonry bearing-wall construction systems are fundamentally two-material, three-phase building systems consisting of masonry units and the means (mortar and skilled labor) necessary to connect them together. In brick masonry, there is brick and mortar (two different materials), and brick-mortar-skill (three phases). The mortar (or jointing system) not only adheres the brick together, but seals the assemblage against weather. But mortar as a joint and sealant is not only weak and brittle, it is also very difficult to apply. The strength and weathertightness of traditional masonry as a construction system is highly dependent on the way in which the joint is made (i.e., workmanship), as well as the inherent structural and other physical characteristics of the bond at the joint.
In conventional construction systems, it is the network of joints (i.e., means of connection) that creates the inherent costly, redundant and sequential erection processes. Although the two-material, three-phase system of bricks and mortar (module-cement skill) is widely used and extremely flexible, it has inherent weaknesses and redundancies which render it less and less economical as a building system.
Although bricks are strong and can individually resist as much as 10,000 psi lead in compression, many building codes limit the allowable amount of tensile bond stress to 10 psi in the connecting interface between brick and mortar in masonry. Traditional masonry is often reinforced with tensile-resistive steel, which adds yet another costly material and redundant step in the construction process. There is thus a reduction of up to 80% in the allowable stress resistant capacity of traditional masonry because of the nature of the mortar and the bond between brick and mortar.
In addition, the nature of the way in which mortar is applied (workmanship) also greatly affects the strength, durability and weathertightness of traditional masonry, and thus building codes further reduce the allowable bearing capacity of masonry by as much as an additional 40% if built with unsupervised labor.
Thus it can be seen that, in traditional construction assemblies, it is the jointing system which requires the skilled labor. It is the nature of the jointing system that determines the nature of the labor involved: welders, riveters, masons, carpenters, etc. Their labor is defined by the type of joints they make. This is so because prior art construction systems conceptually have the joint as something different from, and additional to, the load-bearing structural member.
The great advantages resulting from the precise shape, dimension, and structural uniformity of such masonry blocks does not seem to have been recognized in the art. Likewise, the art has not suggested how such pressure molded masonry units could be economically formed and used to great advantage to assemble structures in a more improved way, particularly a structurally synergistic system of interwoven artificial stone, in which the physical characteristics of the building block and of the assemblage of building blocks are rationally predetermined and predictable.
It is accordingly one important object of the present invention to provide an improved synergistic building system wherein improved structure can be obtained in an improved and synergistic way by assembling precisely shaped and dimensioned integrally interlocking pressure molded masonry building blocks without mortar, thus eliminating the need for a separate and additional jointing system and the time and skill necessary to effect it, i.e., to obtain an improved building system with less time, material, and skilled labor (more-with-less, or true synergy).
Accordingly the present invention provides a building system in which precisely shaped and dimensioned pressure molded masonry building blocks are provided with smooth and parallel surfaces and integral interlocking elements so that a plurality of such precision-made building blocks may be assembled in direct and continuous face-to-face contact between adjacent members without disruption by an intervening thick mortar joint, thus permitting stresses to be transferred directly from one member to the next without the need for an intervening joint or separate and additional "connector".
Another important object of the present invention is to provide improved structure through the use of a one-material, one-phase building system wherein the structural component and the means of connection are one. In other words, it is an important object of the present invention to provide a system of masonry construction with inherent and integral jointing capacity, wherein each masonry building block in itself contains the means of improved connection with another masonry building block, i.e., the novel yin yang jointing system is inherent in the novel building block, thus reducing the number of redundant processes necessary to build structures with a plurality of said building blocks. The assemblage of the whole structure is inherent in and determined by the nature of the individual building block and the geometry of the locking elements. In structures built according to the system of the present invention, for the cost and effort of weaving structural membranes out of a plurality of the improved pressure molded interlocking masonry building blocks of the present invention, the practitioner simultaneously obtains speedier and more efficient "finished" enclosure of space; automatic weathertight and maintenance-free, fireproof construction; thermal and acoustic insulation; inherent structural integrity, strength and stability; durability; permanence, as well as easy assembly and disassembly.
The present invention is advantageous an improved building system wherein improved pressure molded masonry building blocks with integral physically interlocking elements are formed by using a variety of aggregates, such aggregates consisting of any mineral raw material, including aggregates derived as by-products, or as recycled waste materials, from industrial, manufacturing, municipal or other operations.
The foregoing objects are attained together with still other objects which will occur to practitioners from time to time, from considering the building method and building blocks disclosed herein.